This disclosure is directed to an apparatus for creating spaced impressions or grooves in the roadway surface and/or on the shoulders along roadways. The impressions, or grooves are generally used as a warning for drivers that they have moved off the main roadway, or across a lane or dividing line. When the tires of the vehicle contact the grooves, a noise is heard and vibration is felt which alerts the driver that the tires are in contact with the groves and that the driver is moving off the roadway or out of the proper lane. Such impressions, or grooves are frequently referred to as rumble strips. There are a number of apparatus and methods used for moving a grinding tool in and of the the surface to create the grooves, and to do so with proper spacing. The embodiment disclosed herein is directed to an apparatus that is easy to operate, and easy to move between grinding and travelling positions. The apparatus disclosed provides for easy, accurate spacing, and for a method of cutting groups of grooves with a space between the groups.